Ternary precursor with high tap density and method for preparing same

Abstract

Disclosed herein are a ternary precursor with a high tap density and a method for preparing same. The method comprises the following steps: (1) adding a silicon dioxide emulsion into an alkaline substrate solution to give a mixed solution; (2) adding a mixed nickel-cobalt-manganese salt solution, a precipitant, a complexing agent, and a surfactant; (3) conducting solid-liquid separation to give a solid material, and drying and crushing to give a crushed material; (4) mixing the crushed material with the alkaline substrate solution and the surfactant; (5) repeating step (2); and (6) conducting solid-liquid separation to give a solid material, and washing and drying the solid material to give the ternary precursor with a high tap density. The precursor particle prepared according to the method has a higher tap density, and can provide excellent cycle performance for the positive electrode material.

1 . A preparation method for a ternary precursor with high tap density, comprising the following steps:
 (1) adding a silica emulsion to an alkaline base solution under stirring to obtain a mixed liquid;   (2) adding a solution of mixed salts of metal ions of nickel, cobalt, and manganese, a precipitating agent, a complexing agent, and a surfactant to the mixed liquid in step (1) to allow a reaction until D50 of a material in the mixed liquid reaches 1.0 μm to 3.0 μm;   (3) separating the material in step (2) by solid-liquid separation to obtain a solid material, and drying and crushing the solid material to obtain a crushed material;   (4) mixing the crushed material obtained in step (3) with the alkaline base solution and the surfactant to obtain a mixture;   (5) adding the solution of mixed salts of metal ions of nickel, cobalt, and manganese, the precipitating agent, the complexing agent, and the surfactant to the mixture in step (4) to allow a reaction until D50 of a material in the mixture reaches 5.0 μm to 15.0 μm; and   (6) separating the material in step (5) by solid-liquid separation to obtain a solid material, and washing and drying the solid material to obtain the ternary precursor with high tap density;   wherein, the alkaline base solution is a mixed solution of sodium hydroxide and aqueous ammonia, and the alkaline base solution has a pH of 10.0 to 11.0 and an ammonia concentration of 2.0 g/L to 10.0 g/L;   in step (1), the mixed liquid has a silica mass concentration of 1% to 3% and a silica particle size of 1 nm to 100 nm;   in steps (2) and (5), the solution of mixed salts of metal ions of nickel, cobalt, and manganese, the precipitating agent, the complexing agent, and the surfactant are added concurrently, during which a pH of the mixed liquid in step (2) and the mixture in step (5) is controlled at 10.0 to 11.0, an ammonia concentration is controlled at 2.0 g/L to 10.0 g/L, and a flow rate of the surfactant is controlled to be 10% to 100% of a flow rate of the mixed salt solution;   the reactions in steps (2) and (5) are conducted at 45° C. to 65° C.; and   the ternary precursor with high tap density has a general chemical formula of Ni 1-a-b Co a Mn b (OH) 2 ·xSiO 2 , where 0<a<1 and 0<b<1, the ternary precursor with high tap density is composed of secondary particles agglomerated by primary particles, the primary particles are in a shape of blocky cubes and have a particle size of 0.1 μm to 5.0 μm, and the secondary particles obtained by agglomeration have a particle size of 5.0 μm to 15.0 μm.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The preparation method for the ternary precursor with high tap density according to  claim 1 , wherein a total concentration of metal ions of nickel, cobalt, and manganese in the solution of mixed salts of metal ions of nickel, cobalt, and manganese is 1.0 mol/L to 2.5 mol/L. 
     
     
         5 . The preparation method for the ternary precursor with high tap density according to  claim 1 , wherein the precipitating agent is a sodium hydroxide solution with a concentration of 4.0 mol/L to 8.0 mol/L. 
     
     
         6 . The preparation method for the ternary precursor with high tap density according to  claim 1 , wherein the complexing agent is aqueous ammonia with a concentration of 6.0 mol/L to 12.0 mol/L. 
     
     
         7 . The preparation method for the ternary precursor with high tap density according to  claim 1 , wherein the surfactant is at least one of an alkylbenzene sulfonate aqueous solution, an alkylnaphthalene sulfonate aqueous solution, and an alkylsulfonate aqueous solution; and the surfactant has a concentration of 0.1 mol/L to 2 mol/L. 
     
     
         8 . The preparation method for the ternary precursor with high tap density according to  claim 1 , wherein the crushed material obtained in step (3) has a particle size D50 of 100 nm to 500 nm. 
     
     
         9 - 10 . (canceled)